Alkylamines as well as N-alkylalkylenediamines both having alkyl radicals of 8 to 18 carbon atoms are known as antimicrobial substances. However, they have adverse dermatological and toxicological proper ties, which are an obstacle to their use in practice. The reaction products of .epsilon.-caprolactam with N-alkylalkylenediamines in the molar ratio of amine to lactam of 1:1 to 1:10 with alkyl radicals with 10 to 18 carbon atoms, which have an excellent activity on bacteria, fungi and algae, have a much better physiological compatibility. These compounds are described and claimed in U.S. Pat. No. 3,892,806. Antimicrobial and algicidal compositions containing the same are described in U.S. Pat. No. 3,977,859. The specific use of the compounds for water preservation is described in U.S. Pat. Nos. 3,874,869 and 3,965,265. These compounds however, are difficultly soluble and in specific systems are not always sufficiently dispersed, so that for some uses, difficulties may occasionally arise.
In U.S. Pat. No. 3,945,996 adducts of the above-named reaction products of .epsilon.-caprolactam and N-alkylalkylenediamines with epoxy compounds are disclosed, which adducts have improved solubility. Yet in some cases the antimicrobial activity of these substances leaves something to be desired.